arctan⁡xx\arctan{x} is the angle yyy satisfying tan⁡y=xyx\tan y=x and
-π2<y<π2π2yπ2-\frac{\pi}{2}<y<\frac{\pi}{2} (defined in the whole ℝℝ\mathbb{R})

arccot⁡xarccotx\arccot\,{x} is the angle yyy satisfying cot⁡y=xyx\cot y=x and
0<y<π0yπ0<y<\pi (defined in the whole ℝℝ\mathbb{R})

Those functions are denoted also sin-1⁡xsuperscript1x\sin^{{-1}}x, cos-1⁡xsuperscript1x\cos^{{-1}}x, tan-1⁡xsuperscript1x\tan^{{-1}}x and cot-1⁡xsuperscript1x\cot^{{-1}}x. We here use these notations temporarily for giving the corresponding multivalued functions (n=0,±1,±2,…n0plus-or-minus1plus-or-minus2normal-…n=0,\,\pm 1,\,\pm 2,\,...):